A substantial portion of the world's tar sands deposits are situated under a thick overburden which is a layer or rock and soil. Because of a presence of overburden, strip mining of most tar sands becomes extremely costly and essentially prohibitive. Thus, a need has arisen to provide an economical method of mining tar sands located in formations below a thick overburden so that the cost of the energy-providing and other products obtainable from the tar sands will be within reasonable limits compared with corresponding costs of other such products.